Fault code index · Victron VE.Bus, MPPT & VRM

Victron Fault Code Index

Q: Which Victron fault codes clear on their own?

Many do. VE.Bus Error 1 (a phase switched off) and Error 17 (phase master missing) recover automatically once the underlying alarm clears or after a restart. On the MPPT side, Err 2 (battery voltage too high), Err 17/18 (overheat/over-current), Err 33 (PV over-voltage) and Err 39 (PV input shutdown) all auto-reset once conditions return to normal. Err 38, however, does not auto-reset — you recover it by disconnecting the PV then the battery, waiting 3 minutes, and reconnecting the battery first then the panels. If a code keeps coming back after it self-clears, the underlying cause needs diagnosis.

Q: How much does it cost to diagnose a Victron fault code?

The remote diagnostic is free — our engineers review your VRM data, alarm history and settings without visiting site. If we can fix it remotely — a VEConfigure or VictronConnect settings change, a firmware update, or a BMS/standalone setting — it is £75, and you only pay if we actually fix it. If it needs hands-on work, such as DC-side or VE.Bus wiring, we tell you that first. Either way you avoid an unnecessary callout.

Every Victron alarm from the official VE.Bus, MPPT and VRM Portal documentation — what the code means, the most likely cause, and what to do next. Find your code below or browse by system area. Covers MultiPlus, Quattro, SmartSolar, BlueSolar and Cerbo GX.

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Sourced from official Victron documentation — VE.Bus & MPPT error codes and the VRM Portal alarms manual
Linked to full Victron diagnostic guides where available
Covers MultiPlus, Quattro, SmartSolar, BlueSolar and Cerbo GX

Victron fault code you can't resolve?

If your Victron system is showing a VE.Bus or MPPT error, or VRM has sent an alarm and you're unsure what to do next, a remote diagnostic identifies the root cause from your VRM data — typically within 30 minutes.

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39 Customer reviews

My 90-year-old father-in-law had a solar system installed nearly three years ago that never worked properly and kept tripping out. Neither the original installer nor GivEnergy could resolve the issues, and we were even pushed towards replacing the system entirely when GivEnergy went bust. I contacted Ron at Solar Tech Support via WhatsApp, and within a few hours he had diagnosed multiple faults — including incorrect wiring that posed a potential fire risk. He carried out a home visit in Nottingham for £295 (including parts), fixed everything, completed firmware updates, and ensured the system was fully operational. Since then, it has worked perfectly. Ron was knowledgeable, responsive, and took the time to explain everything clearly. Highly recommended — excellent value and complete peace of mind.

Julian F · Jun 2026 Google

My GivEnergy hybrid inverter + battery system had worked faultlessly for 3 years when it suddenly stopped charging and discharging the battery. On contacting my supplier, who had used a sub-contractor for the installation work, I was provided with an email address at GivEnergy but, as it turned out, this is only for GivEnergy Software who are not able to assist. A Google search led to the Solar Tech Support web site, which contains a wealth of helpful information. I requested a remote solar diagnostic, and after providing Ron access to my inverter, he was able to identify and fix the problem within minutes. I am very impressed by Ron’s expertise and knowledge, which included useful information on the current state of GivEnergy Ltd. I would thoroughly recommend Solar Tech Support.

Simon Riddle · Jun 2026 Google

I reached on behalf of a friend, who had lost control of their battery following a storm. A couple giv energy “dealers” had attempted and said different fixes. None worked. Solar tech support solved it remotely on the first attempt almost instantly. Genuinely a 10/10 service.

Will Jay · Jun 2026 Google

I can’t praise this firm enough. After hearing my solar panels rattling in very windy conditions, I contacted Solar Tech (as my installers no longer trade). Ronald was fantastic at explaining what he thought the issue was likely to be. Communication was great throughout keeping me fully updated. The team worked really hard on the day to carry out the necessary work. I can now sleep soundly at night without worrying about the solar panels on my roof. I would thoroughly recommend this firm. Thank you for sorting the problem out.

Carolyn Addison · Jun 2026 Google

Our SolarEdge PV system with LG batteries had its first hiccup after 8 years of hard work. The Inverter failed. Fortunately I found Solar-Tech-Support who diagnosed the problem very quickly, ordered a replacement unit and fitted it shortly after we received the unit from SolarEdge. Very thorough and professional approach. Thank you, a solid 5 star recommendation.

Les Bennett · Jun 2026 Google

STS were incredibly responsive and helpful In diagnosing an issue with my GivEnergy inverter. Although distance meant it was impractical for me to use them to fully solve the issue, I’m grateful for the help and detail they provided. Don is a real professional gent and a hero in my eyes.

Adam Miller · Jun 2026 Google

Julian F · Jun 2026 Google

Simon Riddle · Jun 2026 Google

Will Jay · Jun 2026 Google

Carolyn Addison · Jun 2026 Google

Les Bennett · Jun 2026 Google

Adam Miller · Jun 2026 Google

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How to find your fault code. VE.Bus errors (MultiPlus, Quattro) show on the front-panel LEDs and, with a number, on a connected GX device and in VRM. MPPT "Err" codes (SmartSolar, BlueSolar) appear in the VictronConnect app over Bluetooth, on the controller display, or on a GX device. System alarms (Low battery, Overload, Temperature, High voltage, Communication lost) are named — not numbered — and are pushed from the GX device to VRM. Open VRM and check the alarm log for a timestamped history.

VE.Bus inverter/charger errors (Multi & Quattro)

VE.Bus errors come from MultiPlus, MultiPlus-II and Quattro inverter/chargers. They appear on the front-panel LEDs and, in plain text with a number, on a connected GX device (Cerbo GX, Color Control) and in VRM. Most are shown as "VE.Bus Error" with a number. Several auto-recover the moment the underlying issue clears; others keep the system off until it is restarted. Cabling between units must be machine-made patch leads — never self-crimped cables.

VE.Bus Error 1Device switched off because another phase switched off

In a multi-phase (split-phase or 3-phase) system, one phase shut down and took the others off with it. Error 1 is the knock-on effect, not the root cause — the real fault is a Low battery, Overload or High temperature alarm on one of the other units. Look at the GX device or VRM to see which phase actually raised the Low battery, Overload or Temperature alarm — that is the one to investigate. The system recovers on its own once the underlying alarm clears. If you can't tell which unit is at fault, book a free remote diagnostic and we'll read the VRM logs; FREE to diagnose, £75 only if we fix it.

VE.Bus Error 3Not all (or more than) the expected devices were found

The system can't see the right number of units on the VE.Bus network. Often appears together with Error 1 — fix Error 1 first. Common causes are a blown DC fuse in one unit (everything looks fine on mains, but the unit drops out the moment mains fails), faulty or self-crimped communication cables, or two separate systems wired together by mistake. This usually needs an engineer — DC fuses and the VE.Bus wiring sit inside the units. Note whether it only appears during a power cut (a classic blown-DC-fuse symptom). Do not open the inverter/charger. VE.Bus error guide →

VE.Bus Error 8 / Error 11 Ground relay test failed / Relay test fault

The inverter/charger ran its automatic safety self-test on the internal earth and back-feed relays and it failed, so the unit will not connect to the grid. On MultiPlus-II and EasySolar-II this is most often an installation or wiring problem rather than a broken unit, but it is a protective shutdown and must not be ignored. Causes include neutral-to-earth wiring not done correctly for your installation type, a load with leakage, line and neutral swapped on the input, out-of-date firmware, or — less often — a genuinely failed relay inside the unit. Do not bypass it or keep resetting — the relay test exists to keep the installation safe. This is mains-side wiring and is not a homeowner job. Get the installer or a qualified engineer to check the neutral-earth arrangement, confirm line/neutral aren't swapped, and update firmware. A remote diagnostic can read the detailed step-number the GX device reports and point the engineer straight to the failing check.

VE.Bus Error 17Phase master missing

In systems with more than one unit per phase, a slave unit has lost communication with the phase-master and timed out. If it appears briefly during a restart or while settings are being changed remotely, it's harmless and clears itself. Persistent causes are a cabling/communication problem on the VE.Bus network (bad RJ45 socket or cable), a blown DC fuse stopping a unit powering up when mains is absent, or out-of-date inverter/GX firmware. If it cleared on its own after a restart, no action is needed. If it persists, the network cables, GX device and units may each need checking in turn — an engineer's job, as it involves the wiring between units. Book a diagnostic; we'll review the VRM data first so a site visit (if needed) is targeted.

VE.Bus Error 25Incompatible VE.Bus configuration

The units in the system aren't a legal combination, so the system stays off until it's corrected. Victron only allows units with identical 4-digit type numbers together, and within one phase they must also share the same compatibility letter (e.g. 2623_B). It is caused by mixing inverter/charger models that aren't compatible, or running different firmware versions across the units after a partial update. Check the compatibility code on each unit's sticker (4-digit number plus a letter). Bringing all units to the same latest firmware often resolves it. Firmware and configuration changes are best done by an engineer with VEConfigure — we can do this remotely. FREE to diagnose, £75 only if we fix it.

MPPT solar charger errors (SmartSolar & BlueSolar)

These "Err" numbers come from Victron MPPT solar charge controllers (SmartSolar and BlueSolar). You'll see them in the VictronConnect app over Bluetooth, on the unit's own display where fitted, or on a GX device. Many auto-reset the moment conditions return to normal — the trick is knowing which ones point to a wiring or design problem you should act on.

Err 2Battery voltage too high

The charge controller has measured battery voltage above its safe limit and stopped charging to protect the battery. It auto-resets once the voltage falls back. Causes are another charger also connected to the same battery pushing the voltage up, the battery voltage being set lower in the app than the actual battery (e.g. a 24V pack set as 12V), or — rarely — a fault in the controller. Check in VictronConnect that the battery voltage setting matches your actual battery. If another charger or a DC-coupled source shares the battery, that interaction may be the cause. If the setting is right and it keeps recurring, book a diagnostic — we can read the settings remotely and confirm. Don't touch the DC wiring yourself.

Err 17 / Err 18Controller overheated / over-current

Err 17 means the controller is still too hot even after it cut its own output to reduce heat; Err 18 means the output current went over its safe limit. Both normally auto-reset once things cool down or the surge passes. Err 17 is driven by high ambient temperature or a blocked heatsink/poor airflow; Err 18 by a big load switching on, a sudden jump in sunlight, or an inverter overload pulling hard on the battery. Make sure the controller has clear air around it and isn't in direct sun or a sealed cupboard, and clear any dust from the heatsink. If Err 18 doesn't clear on its own, disconnect the controller from all power sources, wait 3 minutes and power up again. If overheating keeps happening in normal conditions, have it checked.

Err 33PV over-voltage

The voltage coming from the solar panels has exceeded the controller's maximum rated PV input, so it has stopped charging to protect itself. It auto-resets once the PV voltage drops about 5V below the rated maximum. The usual cause is too many panels wired in series for this controller, especially on cold, bright mornings when panel open-circuit voltage is at its highest — a string-design issue. This points to the panel array being configured beyond the controller's limit. Check the array design against the controller's max PV voltage in the datasheet — if it's borderline, the string may need re-arranging, which is an engineer's job (the DC side is live whenever it's light). MPPT error guide →

Err 38 / Err 39PV input shutdown

To protect the battery from overcharging, the controller has internally shorted its own PV input and stopped. Err 38 does not auto-reset; Err 39 resets automatically once the battery voltage drops below the maximum setting. It is caused by an incorrect battery voltage setting, or a conflict where the controller has been told (often by a BMS or a charge limit) to stop charging but the array keeps pushing power in. First, update to the latest firmware in VictronConnect. To recover Err 38: disconnect the solar panels, then the battery; wait 3 minutes; reconnect the battery first, then the panels. If it returns, the battery settings or BMS interaction need looking at — book a remote diagnostic rather than repeatedly forcing it back on. MPPT error guide →

Err 67BMS connection lost

The controller has lost its control connection to the battery's BMS. As a safety measure it drops its output right down to a low base voltage, so the battery barely charges, until communication returns. The cause is a disconnected or faulty communication cable between the charger and the BMS/GX device, or a wider comms failure on the system. Check the communication cable between the charge controller and the BMS (or GX device) is properly seated at both ends. If the controller was deliberately removed from a managed-battery system, its BMS setting may need changing back to standalone in VictronConnect — a settings job we can do remotely. Don't open the battery. FREE to diagnose, £75 only if we fix it. Battery BMS guide →

Err 116Calibration data lost

The controller can't read its factory calibration data. If it's showing as an active error now, the unit is faulty. If it only appears in the history and the charger is working normally, it can be safely ignored. It is either a hardware issue, or (harmlessly, in the log) a side-effect of firmware version changes on SmartSolar units. If it's a live, active error, the controller needs replacing — contact your dealer. If it's only in the event history and everything is charging fine, no action is needed. Unsure which? Book a diagnostic and we'll read the live status to tell you whether it's active or historical.

System, GX & VRM alarms (Cerbo GX / VRM Portal)

These aren't numbered fault codes — they're the named alarms a GX device (Cerbo GX, Color Control GX) raises and pushes to the VRM Portal, which then emails or notifies you. They summarise what the inverter, battery and BMS are reporting. They tell you something needs attention; the matching VE.Bus or MPPT code above usually tells you exactly what.

Low battery alarmBattery voltage critically low (VE.Bus)

The inverter/charger has reported that battery voltage has fallen to a critically low level. In a multi-phase system VRM and the GX device show which phase raised it. The inverter may shut down loads to protect the battery. The battery has been discharged too far — a long spell of high load with little solar or grid charging, an undersized battery for the demand, or a charge source that has failed and left standby loads draining the pack. Reduce or switch off heavy loads and let the battery recharge from solar or grid. If it keeps appearing with the battery seemingly full, the alarm thresholds or wiring may be off — a remote diagnostic can read the VRM history and settings. Repeatedly running a lithium battery flat shortens its life, so don't ignore it.

Overload alarmInverter output overloaded (VE.Bus)

The power being drawn from the inverter/charger has exceeded its rating. The GX device and VRM show which phase is overloaded. The inverter reduces output or shuts down to protect itself. The cause is too many appliances running at once, or a single high-draw load (kettle, oven, immersion heater, a motor starting) exceeding the inverter's continuous rating. Turn off some loads and let the system recover, then stagger high-power appliances rather than running them together. If the overload appears with only modest load connected, that's worth investigating — book a diagnostic and we'll review the VRM power logs. FREE to diagnose, £75 only if we fix it. Inverter overload guide →

Temperature alarmInverter/charger over-temperature (VE.Bus)

The inverter/charger is running too hot and has raised a temperature alarm, throttling output or shutting down until it cools. It is caused by high ambient temperature, the unit installed in a hot or poorly ventilated spot, blocked ventilation, or sustained heavy load. Make sure there's clear air space around the unit, it isn't boxed into a sealed cupboard or sitting in direct sun, and the vents are free of dust. Reduce load if it's been running hard. If it overheats in cool, well-ventilated conditions, the internal fan may have failed — have it checked.

High voltage alarmBattery over-voltage (battery monitor / BMS)

A battery monitor or the battery's BMS has reported pack or cell voltage above its safe limit. On managed lithium batteries this is usually the BMS flagging an internal cell imbalance near the top of charge. Causes are cells drifting out of balance as the pack approaches full, a charge source set too high, or a fault in the battery itself. Often this is a balancing issue best resolved by letting the battery complete a full, supervised charge so the BMS can re-balance the cells, plus keeping the battery firmware up to date. Do not open the battery or alter DC wiring — Victron's guidance for BMS alarms is to involve the supplier. Book a diagnostic and we'll read the cell data from VRM first.

Communication lostInstallation offline / device not communicating

VRM has stopped receiving data from the GX device, or the GX device has lost contact with one of the products in the system. You'll typically get an "installation offline" notification. Causes are loss of internet at the property, the GX device powered down or rebooting, a router problem, or a disconnected network/communication cable to one of the units. Check the GX device is powered on and the property's internet/router is working — a power-cycle of the router and GX device often restores it. If a single product (not the whole site) keeps dropping offline, the cable to that unit may be the issue. We can confirm remotely whether it's an internet outage or a device fault. FREE to diagnose, £75 only if we fix it. VRM offline guide →

Code not listed here?

Victron's VE.Bus and MPPT error lists grow with firmware updates, and the named GX/VRM alarms summarise what the inverter and battery BMS report rather than using a fixed number. If your code isn't listed, share the exact text from VictronConnect, the GX device, or the VRM alarm log and we'll identify it. Victron's own VE.Bus and MPPT error pages and the VRM Portal manual are the authoritative references.

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Full diagnostic guides by fault type

VE.Bus Error 1 · 3 · 8 · 11 · 17 · 25

VE.Bus error codes

Full diagnostic — MultiPlus & Quattro communication, blown DC fuses, the ground/relay safety self-test, and self-crimped cable faults.

Err 2 · 17 · 18 · 33 · 38 · 39 · 67

MPPT error codes

SmartSolar & BlueSolar — PV over-voltage string design, PV input shutdown recovery, overheating, and BMS connection loss.

No charge · DVCC · charge parameters

MultiPlus not charging

Charge parameters, BMS lockout, AC input current limit, firmware mismatch, and DVCC configuration on grid and off-grid systems.

High voltage · BMS lost · Err 67

Battery BMS disconnect

Third-party lithium BMS cut-outs — cell imbalance, low-temperature charge protection, SoC drift, and DVCC settings.

Communication lost · Cerbo GX · WiFi

VRM portal / Cerbo GX offline

Installation-offline alarms — WiFi dropout, Ethernet DHCP, static IP, and VRM access token issues on the GX device.

FAQ

Victron fault code questions

Where do I find fault codes on my Victron system?

VE.Bus errors from a MultiPlus or Quattro show on the front-panel LEDs and, with a number and plain-text description, on a connected GX device (Cerbo GX or Color Control) and in the VRM Portal. MPPT errors from SmartSolar and BlueSolar charge controllers appear in the VictronConnect app over Bluetooth, on the controller's own display where fitted, or on a GX device. System-level alarms (Low battery, Overload, Temperature, High voltage, Communication lost) are raised by the GX device and pushed to VRM, which can email or notify you. For a full history, open VRM and check the alarm log.

Which Victron fault codes clear on their own?

Many do. VE.Bus Error 1 (a phase switched off) and Error 17 (phase master missing) recover automatically once the underlying alarm clears or after a restart. On the MPPT side, Err 2 (battery voltage too high), Err 17/18 (overheat/over-current), Err 33 (PV over-voltage) and Err 39 (PV input shutdown) all auto-reset once conditions return to normal. Err 38, however, does not auto-reset — you recover it by disconnecting the PV then the battery, waiting 3 minutes, and reconnecting the battery first then the panels. If a code keeps coming back after it self-clears, the underlying cause needs diagnosis.

What does a Victron VE.Bus Error 8 or Error 11 mean?

Error 8 (ground relay test failed) and Error 11 (relay test fault) mean the inverter/charger ran its automatic safety self-test on the internal earth and back-feed relays and it failed, so the unit will not connect to the grid. On MultiPlus-II and EasySolar-II it is most often an installation or wiring problem — incorrect neutral-to-earth wiring for your installation type, a load with leakage, line and neutral swapped on the input, or out-of-date firmware — rather than a broken unit, but it is a protective shutdown that must not be bypassed or repeatedly reset. This is mains-side wiring and is not a homeowner job; get a qualified engineer to check the neutral-earth arrangement and update firmware. See our full VE.Bus error guide.

What causes Victron MPPT Err 33 and Err 38?

Err 33 (PV over-voltage) means the voltage from the solar panels has exceeded the controller's maximum rated PV input, so it has stopped charging to protect itself — usually too many panels wired in series for that controller, most likely to trigger on cold, bright mornings when panel open-circuit voltage is highest. It auto-resets once PV voltage drops about 5V below the rated maximum. Err 38 (PV input shutdown) means the controller has internally shorted its own PV input to stop the battery overcharging, typically from an incorrect battery voltage setting or a BMS/charge-limit conflict. Err 38 does not auto-reset: disconnect the panels then the battery, wait 3 minutes, reconnect the battery first then the panels, and update firmware in VictronConnect. See our full MPPT error guide.

How much does it cost to diagnose a Victron fault code?

The remote diagnostic is free — our engineers review your VRM data, alarm history and settings without visiting site. If we can fix it remotely — a VEConfigure or VictronConnect settings change, a firmware update, or a BMS/standalone setting — it is £75, and you only pay if we actually fix it. If it needs hands-on work, such as DC-side or VE.Bus wiring, we tell you that first. Either way you avoid an unnecessary callout.

How quickly can you diagnose a Victron fault?

Usually the same day. Most Victron faults are confirmed in a single 30-minute remote session — we read your VRM alarm history and live data while you describe what the system is doing. You get a written summary of the cause and the recommended fix straight after the call.

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